Motorbike purchase (Kampala)

Could someone tell me what I need to do to buy a Motorbike in Kampala. I have a full UK driving license but that's it, are there licences I will need out there? I would also be thankful for any information on where and how to buy a bike, perhaps from new, I was thinking about a Yamaha Protected content they will be more reliable than the ubiquitous Bajaj 100s seen everwhere